Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2012 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_ELEMENTS_KIND_H_ |
| 6 | #define V8_ELEMENTS_KIND_H_ |
| 7 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 8 | #include "src/base/macros.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 9 | #include "src/checks.h" |
| 10 | |
| 11 | namespace v8 { |
| 12 | namespace internal { |
| 13 | |
| 14 | enum ElementsKind { |
| 15 | // The "fast" kind for elements that only contain SMI values. Must be first |
| 16 | // to make it possible to efficiently check maps for this kind. |
| 17 | FAST_SMI_ELEMENTS, |
| 18 | FAST_HOLEY_SMI_ELEMENTS, |
| 19 | |
| 20 | // The "fast" kind for tagged values. Must be second to make it possible to |
| 21 | // efficiently check maps for this and the FAST_SMI_ONLY_ELEMENTS kind |
| 22 | // together at once. |
| 23 | FAST_ELEMENTS, |
| 24 | FAST_HOLEY_ELEMENTS, |
| 25 | |
| 26 | // The "fast" kind for unwrapped, non-tagged double values. |
| 27 | FAST_DOUBLE_ELEMENTS, |
| 28 | FAST_HOLEY_DOUBLE_ELEMENTS, |
| 29 | |
| 30 | // The "slow" kind. |
| 31 | DICTIONARY_ELEMENTS, |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 32 | |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 33 | // Elements kind of the "arguments" object (only in sloppy mode). |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 34 | FAST_SLOPPY_ARGUMENTS_ELEMENTS, |
| 35 | SLOW_SLOPPY_ARGUMENTS_ELEMENTS, |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 36 | |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 37 | // For string wrapper objects ("new String('...')"), the string's characters |
| 38 | // are overlaid onto a regular elements backing store. |
| 39 | FAST_STRING_WRAPPER_ELEMENTS, |
| 40 | SLOW_STRING_WRAPPER_ELEMENTS, |
| 41 | |
| 42 | // Fixed typed arrays. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 43 | UINT8_ELEMENTS, |
| 44 | INT8_ELEMENTS, |
| 45 | UINT16_ELEMENTS, |
| 46 | INT16_ELEMENTS, |
| 47 | UINT32_ELEMENTS, |
| 48 | INT32_ELEMENTS, |
| 49 | FLOAT32_ELEMENTS, |
| 50 | FLOAT64_ELEMENTS, |
| 51 | UINT8_CLAMPED_ELEMENTS, |
| 52 | |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 53 | // Sentinel ElementsKind for objects with no elements. |
| 54 | NO_ELEMENTS, |
| 55 | |
| 56 | // Derived constants from ElementsKind. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 57 | FIRST_ELEMENTS_KIND = FAST_SMI_ELEMENTS, |
| 58 | LAST_ELEMENTS_KIND = UINT8_CLAMPED_ELEMENTS, |
| 59 | FIRST_FAST_ELEMENTS_KIND = FAST_SMI_ELEMENTS, |
| 60 | LAST_FAST_ELEMENTS_KIND = FAST_HOLEY_DOUBLE_ELEMENTS, |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 61 | FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = UINT8_ELEMENTS, |
| 62 | LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = UINT8_CLAMPED_ELEMENTS, |
| 63 | TERMINAL_FAST_ELEMENTS_KIND = FAST_HOLEY_ELEMENTS |
| 64 | }; |
| 65 | |
| 66 | const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1; |
| 67 | const int kFastElementsKindCount = LAST_FAST_ELEMENTS_KIND - |
| 68 | FIRST_FAST_ELEMENTS_KIND + 1; |
| 69 | |
| 70 | // The number to add to a packed elements kind to reach a holey elements kind |
| 71 | const int kFastElementsKindPackedToHoley = |
| 72 | FAST_HOLEY_SMI_ELEMENTS - FAST_SMI_ELEMENTS; |
| 73 | |
| 74 | int ElementsKindToShiftSize(ElementsKind elements_kind); |
| 75 | int GetDefaultHeaderSizeForElementsKind(ElementsKind elements_kind); |
| 76 | const char* ElementsKindToString(ElementsKind kind); |
| 77 | |
| 78 | inline ElementsKind GetInitialFastElementsKind() { return FAST_SMI_ELEMENTS; } |
| 79 | |
| 80 | ElementsKind GetFastElementsKindFromSequenceIndex(int sequence_number); |
| 81 | int GetSequenceIndexFromFastElementsKind(ElementsKind elements_kind); |
| 82 | |
| 83 | ElementsKind GetNextTransitionElementsKind(ElementsKind elements_kind); |
| 84 | |
| 85 | inline bool IsDictionaryElementsKind(ElementsKind kind) { |
| 86 | return kind == DICTIONARY_ELEMENTS; |
| 87 | } |
| 88 | |
| 89 | |
| 90 | inline bool IsSloppyArgumentsElements(ElementsKind kind) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 91 | return kind == FAST_SLOPPY_ARGUMENTS_ELEMENTS || |
| 92 | kind == SLOW_SLOPPY_ARGUMENTS_ELEMENTS; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 93 | } |
| 94 | |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 95 | inline bool IsStringWrapperElementsKind(ElementsKind kind) { |
| 96 | return kind == FAST_STRING_WRAPPER_ELEMENTS || |
| 97 | kind == SLOW_STRING_WRAPPER_ELEMENTS; |
| 98 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 99 | |
| 100 | inline bool IsFixedTypedArrayElementsKind(ElementsKind kind) { |
| 101 | return kind >= FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND && |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 102 | kind <= LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND; |
| 103 | } |
| 104 | |
| 105 | |
| 106 | inline bool IsTerminalElementsKind(ElementsKind kind) { |
| 107 | return kind == TERMINAL_FAST_ELEMENTS_KIND || |
| 108 | IsFixedTypedArrayElementsKind(kind); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 109 | } |
| 110 | |
| 111 | |
| 112 | inline bool IsFastElementsKind(ElementsKind kind) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 113 | STATIC_ASSERT(FIRST_FAST_ELEMENTS_KIND == 0); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 114 | return kind <= FAST_HOLEY_DOUBLE_ELEMENTS; |
| 115 | } |
| 116 | |
| 117 | |
| 118 | inline bool IsTransitionElementsKind(ElementsKind kind) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 119 | return IsFastElementsKind(kind) || IsFixedTypedArrayElementsKind(kind) || |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 120 | kind == FAST_SLOPPY_ARGUMENTS_ELEMENTS || |
| 121 | kind == FAST_STRING_WRAPPER_ELEMENTS; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 122 | } |
| 123 | |
| 124 | |
| 125 | inline bool IsFastDoubleElementsKind(ElementsKind kind) { |
| 126 | return kind == FAST_DOUBLE_ELEMENTS || |
| 127 | kind == FAST_HOLEY_DOUBLE_ELEMENTS; |
| 128 | } |
| 129 | |
| 130 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 131 | inline bool IsFixedFloatElementsKind(ElementsKind kind) { |
| 132 | return kind == FLOAT32_ELEMENTS || kind == FLOAT64_ELEMENTS; |
| 133 | } |
| 134 | |
| 135 | |
| 136 | inline bool IsDoubleOrFloatElementsKind(ElementsKind kind) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 137 | return IsFastDoubleElementsKind(kind) || IsFixedFloatElementsKind(kind); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 138 | } |
| 139 | |
| 140 | |
| 141 | inline bool IsFastSmiOrObjectElementsKind(ElementsKind kind) { |
| 142 | return kind == FAST_SMI_ELEMENTS || |
| 143 | kind == FAST_HOLEY_SMI_ELEMENTS || |
| 144 | kind == FAST_ELEMENTS || |
| 145 | kind == FAST_HOLEY_ELEMENTS; |
| 146 | } |
| 147 | |
| 148 | |
| 149 | inline bool IsFastSmiElementsKind(ElementsKind kind) { |
| 150 | return kind == FAST_SMI_ELEMENTS || |
| 151 | kind == FAST_HOLEY_SMI_ELEMENTS; |
| 152 | } |
| 153 | |
| 154 | |
| 155 | inline bool IsFastObjectElementsKind(ElementsKind kind) { |
| 156 | return kind == FAST_ELEMENTS || |
| 157 | kind == FAST_HOLEY_ELEMENTS; |
| 158 | } |
| 159 | |
| 160 | |
| 161 | inline bool IsFastHoleyElementsKind(ElementsKind kind) { |
| 162 | return kind == FAST_HOLEY_SMI_ELEMENTS || |
| 163 | kind == FAST_HOLEY_DOUBLE_ELEMENTS || |
| 164 | kind == FAST_HOLEY_ELEMENTS; |
| 165 | } |
| 166 | |
| 167 | |
| 168 | inline bool IsHoleyElementsKind(ElementsKind kind) { |
| 169 | return IsFastHoleyElementsKind(kind) || |
| 170 | kind == DICTIONARY_ELEMENTS; |
| 171 | } |
| 172 | |
| 173 | |
| 174 | inline bool IsFastPackedElementsKind(ElementsKind kind) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 175 | return kind == FAST_SMI_ELEMENTS || kind == FAST_DOUBLE_ELEMENTS || |
| 176 | kind == FAST_ELEMENTS; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 177 | } |
| 178 | |
| 179 | |
| 180 | inline ElementsKind GetPackedElementsKind(ElementsKind holey_kind) { |
| 181 | if (holey_kind == FAST_HOLEY_SMI_ELEMENTS) { |
| 182 | return FAST_SMI_ELEMENTS; |
| 183 | } |
| 184 | if (holey_kind == FAST_HOLEY_DOUBLE_ELEMENTS) { |
| 185 | return FAST_DOUBLE_ELEMENTS; |
| 186 | } |
| 187 | if (holey_kind == FAST_HOLEY_ELEMENTS) { |
| 188 | return FAST_ELEMENTS; |
| 189 | } |
| 190 | return holey_kind; |
| 191 | } |
| 192 | |
| 193 | |
| 194 | inline ElementsKind GetHoleyElementsKind(ElementsKind packed_kind) { |
| 195 | if (packed_kind == FAST_SMI_ELEMENTS) { |
| 196 | return FAST_HOLEY_SMI_ELEMENTS; |
| 197 | } |
| 198 | if (packed_kind == FAST_DOUBLE_ELEMENTS) { |
| 199 | return FAST_HOLEY_DOUBLE_ELEMENTS; |
| 200 | } |
| 201 | if (packed_kind == FAST_ELEMENTS) { |
| 202 | return FAST_HOLEY_ELEMENTS; |
| 203 | } |
| 204 | return packed_kind; |
| 205 | } |
| 206 | |
| 207 | |
| 208 | inline ElementsKind FastSmiToObjectElementsKind(ElementsKind from_kind) { |
| 209 | DCHECK(IsFastSmiElementsKind(from_kind)); |
| 210 | return (from_kind == FAST_SMI_ELEMENTS) |
| 211 | ? FAST_ELEMENTS |
| 212 | : FAST_HOLEY_ELEMENTS; |
| 213 | } |
| 214 | |
| 215 | |
| 216 | inline bool IsSimpleMapChangeTransition(ElementsKind from_kind, |
| 217 | ElementsKind to_kind) { |
| 218 | return (GetHoleyElementsKind(from_kind) == to_kind) || |
| 219 | (IsFastSmiElementsKind(from_kind) && |
| 220 | IsFastObjectElementsKind(to_kind)); |
| 221 | } |
| 222 | |
| 223 | |
| 224 | bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind, |
| 225 | ElementsKind to_kind); |
| 226 | |
| 227 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 228 | inline ElementsKind GetMoreGeneralElementsKind(ElementsKind from_kind, |
| 229 | ElementsKind to_kind) { |
| 230 | if (IsMoreGeneralElementsKindTransition(from_kind, to_kind)) { |
| 231 | return to_kind; |
| 232 | } |
| 233 | return from_kind; |
| 234 | } |
| 235 | |
| 236 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 237 | inline bool IsTransitionableFastElementsKind(ElementsKind from_kind) { |
| 238 | return IsFastElementsKind(from_kind) && |
| 239 | from_kind != TERMINAL_FAST_ELEMENTS_KIND; |
| 240 | } |
| 241 | |
| 242 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 243 | } // namespace internal |
| 244 | } // namespace v8 |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 245 | |
| 246 | #endif // V8_ELEMENTS_KIND_H_ |